There is a reason he had to be written out of the story until after Shibuya.
Had he been allowed to partake, the shibuya incident would have been known as "the shibuya inconvenience" instead.
Fatherhood is the end of philosophy. you can read every book ever written about meaning and purpose and discipline, but the moment a small human looks at you and believes you, everything you thought you knew burns down. because now you have to do it, not think it, not debate it, not post about it. the child watches your hands, what you do when you are tired, what you do when you are mad, what you do when nobody else is looking. that is your only sermon and you cannot fake it for one day because children are bullshit detectors made of flesh. if you are a weak man your son will know it before he can spell the word weak, and he either becomes you or becomes the opposite of you, both out of desperation.